Improvement in fire-extinguishers



UNITED STATES PATENT OEEIcE.

WILLIAM M. PARKER, oF BOSTON, MASSACHUSETTS,

IMPROVEMENT IN FIRE-l-EX'TINGUISHERS.

Spcciiication forming part of Letters Patent No. 88,583, dated April 6,1869.

My invention relates to portable chemical hre-extinguishers, in whichthe expansive force of carbonio-acid gas is employed for expellingaerated water from a closed vessel and throwing it upon the fire.

That water charged with 4carbonio-acid gas is more effective inextinguishing fire than water not so charged is a well-known chemicalfact, which has been practically illustrated an d established in thisand other countries, mainly by the use of a portable apparatus called lalire-extin guisher.7

In the only apparatus of this kind heretofore manufactured for publicsale and use, the ingredients which are relied upon for the productionof the carbonio-acid gas employed are brought into contact when thevessel is charged, and the full volume of gas is soon eliminated,creating a pressure of sixty to eighty pounds or more to the squareinch.

The apparatus must remain absolutely gastight-under this pressure untilthe occasion arises for using it, as the least escape would soon soreduce the small volume required to charge a portable vessel of suitablecapacity .as to entirely defeat the object of charging it.

It being impracticable to construct apparatus which, especially in thehands of inexperienced persons, can be relied upon to hold gas undersuch a pressure for a greatlen gth of time, the practice is resorted toof constantly watching these charged receptacles and testing them withthe pressure-gage, and recharging them more less frequently, accordingto the amount of leakage, involving a good deal of care, trouble,4 andexpense, and rendering the apparatus ot' questionable utility.

To obiate the difficulty above named, it has been proposed to keep theingredients entirely separate until the occasion for using the machineoccurs, and then bring them together at once and quickly eliminate thefull volume of gas and play upon the lire; but by this plan the greatadvantage of using aerated water in extinguishing flre is nearly lost.The gas in such a case, by its great buoyancy, is forced into the upperpart of the vessel, and but a small proportion of it passes out with thewater, and what does pass out is only in aforced mechanical mixture withthe water, except a very small volume, which may be quickly dissolvedunder such circumstances, and it escapes from the stream with greatrapidity, so that but a little of it gets more than a few yards from thehose-pipe.

Water `chemically dissolves carboni-c acid gas, and will hold iusolution more than its own volume at the temperature of 600 Fahrenheitwithout exertin g anypressure upon a closed vessel filled with it. Thisgas, so dissolved in water, will pass with it anypracticable distancewithout escaping from the stream, and when carried onto a re it isquickly expanded into several times its previous volume, and,escapingfro m the water or min glin g with its vapor, envelops the burningmaterial with an atmosphere fatal to combustion. But carbonic-acid gasis not at once dissolved by water, except to a very limited extent, evenwhen they are forced into contact in a closed vessel. timeis required,unless the water is a good deal'agitated, as in charging asoda-fountain. Hence the great advantage of this chemical union of thegas with the water in a chemical hre-extinguisher is nearly lost if noneof the gas be eliminated until the occasion arises for using theapparatus. Y

The plan of my invention is, so far as it relates to the above-namedpoints, to eliminate as much gas, or thereabout, when the vessel isfirst charged, as the water will holdin solution at the lowesttemperature to which it is liable to be subjected, and under such slightpressure as I can always be controlled with well-made apparatus for anylength of time or without any pressure after the gas is dissolved atordinary temperatures, and allow the apparatus to remain in thiscondition until it is used, and then, when the occasion occurs, by asimple operation, bring the remaining portions of the ingredient-Ssuddenly and Several hours rapidly into contact, and in a few secondsproduce whatever pressure is required to throw y the water upon thetire, carrying with it the gas previously held by it, and about as muchin addition as would be carried if none had been previously eliminatedand dissolved.

A, Fig. 1, is a perspective view of the main receptacle, which is madeof' sheet metal, and of sufcient strength to sustain a pressure of atleast one hundred and fifty pounds to the square inch. C is theoutlet-cock, to which a suitable hose, terminating in a small jet-pipe,is to be att-ached. B is a strap, by which the apparatus is suspendedupon the left breast and side of the operator, the strap being .passedover the head and under the left arm and obliquely across the breast,the main weight being supported upon the right shoulder. The mainopening in this vessel is in the center of the bottom end, into which issoldered upon the inside a iianged ring or bush, into which thescrew-plug a, Fig. 2, is screwed.

The tube b, Fig. 2, is open at one end, with a hole in the center oftheopposite end. Into this tube is lirst dropped the acid=vessel c, Fig. 2,bottom up, the neck or projection d d passing through the hole in theend of the tube. Then into the samen tube is put the acidvessel e, theopen end up and the bottom resting upon the bottom of acid-vessel c.Tube b is then attached to an inner exten sion of screwplug a in such amanner as to be readily detachable.

To the neck of acid-vessel c is fitted the tubefplug f, which, whendrawn out so as to bring up on the inside, serves as a solid stopper tothe vessel, but when pushed in allows any liquid contents to ilow out,the vessel be- -ing bottom up. The collar on the outer end .of thestopper is attached after the vessel is passed into the tube.

The socket g g, Fig. 2, is attached to the center of the inside ofthetop end of the main vessel.

Between the bottom of this socket Vand the head of the vessel, to whichit is attached, a small space is left to allow the gas, when the machineis used, free access through the holes h h to the escape-cock d, Fig. l.The primary object of this socket is to receive and support in positionthe inner end of the tube b.

Sulphuric acid is the cheapest, most abundant, and most reliable acidsuitable'to be employed in veliminating carbonio-acid gas from thecommon carbonates The acidvessel in a portable tire extinguisher shouldbe nearly the length of the mainvessel, that it may be as small aspossible in diameter, because the smaller the opening in the main vesselthe more readily it can be made gas-tight under pressure.

1f sulphurlc acid or strong solutions of tartaric, oxalic, or othersolid acids are used, and are kept unneutralized any great length oftime, lead vessels should be employed for holdingthem. The sides of alead vessel for such use should be as thin as possible to avoid weight;but a long vessel or tube ofnthin lead is easily bent out of shape andposition.

One object of my invention .is to provide for the convenient use of suchvessels in a portable iire-cx'tinguisher, which I accomplish by means ofthe tube b and socket g g, Fig. 2.

It is obvious that one acid-vessel, with two compartments, may beemployed, instead oi the two vessels above named, or that the two may beattached to each other at their closed ends.

By means of' the bottom or partition 'j of thesocket g g. the tube-plugin acid-vessel C is pushed in as the screw-plug a is screwed down, thatthe contents of the vessel may tlow out.

When a portable chemical fire-extinguisher is charged it is not knownwhether its use will be required in cold orhot weather, or what will bethe temperature of the place in which it will be used, in consequence ofthe heat of the iire to be extinguished.

The chemical ingredients must be suficient to produce an ample volume ofgas at the lowest temperature to which the contents of the vessel areliable to be reduced when the machine is used 5 yet a suitable volume ofgas at a temperature near the freezing-point of water would be soincreased in expansive force-in very hot weather, or in a heated room,or in the neighborhood of a hot iire, that the very small jet of waternecessarily used would be liable to bebroken into spray and mist withina few feet of the jet-pipe.

The expansive force of carbonio-acid gas is more increased by the sameincrease of temperature than that of atmospheric air or any otherpermanent gas.

To insure the usefulness of such an apparatus under widely-varyin gtemperatures, with a uniform charge of chemical ingredients, itv

is essential that the operator should have a ready means of reducingexcessive pressure. To meet this requirement the device marked d, Fig.1, is provided. By unscrewing the screw-plug tk, Fig. 2, the gas escapesthrough the passage m. v

To charge the machine, place it bottom up, unscrew the screw-plug a,with the tube and acid-vessels attached. Fill the vessel so full with asolutionof the bicarbonate of soda or other carbonate that when the tubeand acidvessels are returned the water will not be quite up to the openend of the upper acidvessel. lf the bicarbonate of soda be used, put inabout two and a halt' ounces to every gallon of water. Without detaching the tube from the screw-plug, hold it upright, with the screw-plugdown. Push in the tube-plug of the acid-vessel, now uppermost, until thecollar on the end rests on the neck of the vessel. Pour the acid intothe tube end ot' the plug, and it will pass into the vessel through thelateral holes at the bottom of the tube part of the plug. Draw the plugout until it brings up on the inside, for the purpose of tempora rilystopping the mouth ofthe vessel. Insert the tube and detach it from thescrew-plug, and pour into the other acid-vessel, now uppermost, therequisite quantity of acid. Attach the. tube to the screw-plug and passit into the vessel, and screw in the screw-plug. When the screw isnearly home the end of the stopper of the lower acid-vessel will strikethe bottom of the socket and be pushed in, so that the acid will ow out,and, mingling with the alkaline solution, will eliminate a volume ofcarbonio-acid gas in exact proportion ,to the quantity and strength ofthe acid in the vessel.

The apparatus is to remain bottom up until the occasion for using itoccurs, when it is to be inverted, which will allow vthe acid in thelarger vessel to tlowout, and produce, with great rapidity, therequisite volume of gas to expel with sufcient force the contents of thevessel. This la st charge of acid should be ordinarily about doubletheamount of the rst, and both together should never exceed the amountrequired to neutralize the carbonate dissolved in the water. v

It is obvious that a solid acid can be used in lien of the liquid acidin the smaller vessel, as herein contemplated, in which case the smallervessel can be dispensed with, and, a suitable device being provided tokeep the larger vessel in position, the solid acid can be put into thelowerpart of the tube b and coniined there until dissolved out bycontact with the solution through holes made in the body of the tube. Alarger tube would be required to meet the case.

Solid acids are more bulky, less reliable, and require more time toeffect the same results.

1. I claim so introducing, managing, and controlling the acid employedin charging a portable chemical fire-extinguisher that any requiredportion of the carbonio-acid gas due to the union of the ingredientsused lmay be eliminated at or about the time of charging, and theremaining portion ,at any time thereafter, in the manner and by themeans herein described, substantially as and for the purpose set forth.y

2. I claim introducing the acid employed in charging a portable chemicalnre-extinguisher in two separate portions by means of two acid vesselsor compartments, so that one portion shall be brought into chemicalunion with the alkaline solution contained in the main receptacle at thetime of charging, automatically, or, by reason of the peculiarconstruction of the apparatus and the other portion, brought into suchunion at any time thereafter by the voluntary agency of the operator,substantially as herein described, and for the purposes set forth.

3. I claim, in a portable chemical fire-extinguisher, the use of thesocket g g, Fig. 2, or its mechanical equivalent, to aid in sustainingin position the acid vessel or vessels employed in the construction anduse of the apparatus, and regardless of :its use, as herein described,in liberating the contents of the smaller acidvessel.

4. I .claim controlling the pressure of gas in a portable chemicaltire-extinguisher by the means herein described, substantially as andfor the purposes set forth.

In testimony whereof I have hereunto subscribed my name.

WM. M. PARKER.

Witnesses:

A. B. ELY, JAS. M. WHITTEMORE.

